The trial for three Calgary police officers charged with assault after they seriously injured a man during an arrest has been delayed by five months after one of the trio's lawyers was appointed to the Court of Queen's Bench last week.

Prior to his appointment, defence lawyer Willie deWit was on retainer with the Calgary Police Association, specializing in representing officers facing legal trouble. He had been representing Const. Kevin Humfrey, 33, who is charged with assault causing bodily harm and two counts of public mischief in connection with the July 2016 arrest of Clayton Prince, 34.

The other two officers are Const. James Othen, 38, who faces four charges including assault causing bodily harm, assault with a weapon and two counts of public mischief, and Const. Michael Sandalack, 31, who faces a charge of assault causing bodily harm.

The officers are accused of assaulting Prince during an arrest, leaving him with a collapsed lung and broken ribs.

On Tuesday, provincial court Judge Bruce Fraser allowed lawyers for Othen and Sandalack to vacate this week's trial dates after a Vancouver lawyer, who also specializes in representing police officers, signed on to represent Humfrey.

The officers only came under investigation after video from a police dashcam surfaced that contradicted their accounts of the incident.

Other Calgary Police Service officers flagged the video to their supervisors, according to the Alberta Serious Incident Response Team.

Charges Prince faced of resisting arrest and possession of marijuana were stayed after the officers were charged.

Trial now set for August

Edmonton Crown Jim Stewart is prosecuting the case to avoid conflict and an out-of-town judge has been ordered.

Stewart gave Paul Brunnen and Alain Hepner — who represent Sandalack and Othen — the option to run the trial this week without Humfrey, but they made the decision to wait for the third accused.

"I personally believe it's a better economic use of resources," said Hepner.